The present invention relates to wire belts and in particular, to a wire belt having a compound linking portion formation.
Wire belts are commonly used for conveying articles during cooling, drying, coating, cooking and many other applications. In one particular application, during the processing of poultry, wire belts are utilized for breading and battering lines wherein the product to be conveyed is first covered with batter, then covered with a breading, and finally transported to an oven for baking. Wire belts are advantageous for this and other types of food processing applications because they provide an open, flow-through mesh, a high degree of flexibility, a sanitary construction, simple installation and maintenance, and the ability to be positively driven. As the demands of production increase, however, the amount of product conveyed must be increased and the wire belt must support heavier loads and be driven faster, resulting in an increased strain on the wire belts. Existing wire belts have been unable to satisfactorily meet this increased production requirement.
Existing wire belts 10, as shown in FIG. 1, are typically made of interlocking wire links 12 that form the open mesh and provide a flexible belt that is suited to the above applications. The wire links 12 of existing wire belts 10 include linking portions 14 that are interlocked or linked with linking portions 14 of an adjacent wire link 12.
Each of the wire links 12, as shown in FIG. 2, is formed by a zig-zag strand of wire, generally one-half to three-quarter hard 302 stainless steel. The wire link 12 has an undulating shape, such as a modified square sine wave shape. The linking portions 14 of the wire links are defined by the zig-zag or Z-shaped elements spaced along the length of the wire link. The Z-shaped linking portions 14 of adjacent wire links 12 are joined together so as to form a continuous conveyor belt having a predetermined length. The interlocked linking portions 14 form a number of joints 16 and open spaces 18 in the wire belt 10. The open spaces 18 are defined by the distance between adjacent wire links 12, generally expressed as the number of strands per foot or the xe2x80x9cpitchxe2x80x9d (P) of the belt, and the xe2x80x9cspacing widthxe2x80x9d (A) of the linking portions 14. The xe2x80x9cmeshxe2x80x9d of a wire belt 10 is defined as a combination of the pitch P and wire diameter.
The open spaces 18 defined between the plurality of rows or wire links 12 of the belt 10 allow the belt to bend around a sprocket or roller in the direction of travel. This bending of the wire belt 10 is also referred to as hinging. Similarly, when the wire belt is caused to bend around a sprocket or roller in a direction opposite to the direction of travel, the wire belt is said to be in a reverse bend.
The interlocking of the Z-shaped linking portions 14 produces a small gap 20 between the linking portion 14 of a first wire link and the mating linking portion 14 of an adjacent wire link. This small gap 20 is shown in an enlarged view in FIG. 3 for clarity. The gap between the linking portions 14 of adjacent wire links 12 allows the wire belt 10 to shift laterally as it is running and thus mis-track such that the conveyor belt does not run straight. The interaction of the Z-shaped linking portions 14 also causes the wire links to stress one another along the contact points therebetween when the conveyor belt traverses a shaft, sprocket, or other conveying element. The increased stress encountered in turns leads to metal fatigue and premature failure of the wire belt. It is a common occurrence therefore that production must be shut down to fix the broken wire links in the wire belt and to replace prematurely damaged belts in processing lines.
A further problem associated with conventional wire belts concerns edge damage. As a conveyor belt runs, over time the gap 20 between the linking portions 14 accumulates to one side of the wire belt 10. In order to compensate for the lateral shifting of the conveyor belt, manufacturers of such belts have generally recommended that the linking portions 14 be spaced at least one-eighth inch from the sprockets of the conveyor belt. In this way, as the belt laterally shifts during use, the danger of the linking portions becoming entangled within a sprocket or other driving element is reduced. The edge loop 22 on the edge of the wire belt 10, however, still experiences a significant degree of movement which results in edge loop flaring as the open loops continually catch on the conveyor belt rails or other components. Accordingly, there is a need for a wire belt having an increased belt strength and longer belt life to provide product support during the conveyance thereof, such as in the processing of food.
In order to overcome the deficiencies of prior wire belts, the present invention features a wire belt with an increased belt strength and resultant extended belt life. The wire belt includes a plurality of wire strands each of which is linked with at least one adjacent wire strand in the wire belt. Each wire strand includes a first end and a second end and a plurality of linking portions between the first end and the second end. The plurality of linking portions are linked with respective linking portions in an adjacent wire strand forming a plurality of joints in the wire belt. Each of the plurality of linking portions includes a compound Z-shape formation, which preferably includes an upper member, a compound angle diagonal member, and a lower member.
In a further aspect of the present invention, the compound angle diagonal member includes a first member, a central member extending therefrom, and a second member extending from the central member, with the first member and the central member forming a first included angle and the central member and the second member forming a second included angle. The first included angle and the second included angle may be substantially the same, and in a preferred embodiment the first included angle and the second included angle are defined by an angle greater than ninety degrees and less than one hundred eighty degrees.
In a still further aspect of the invention the upper member and the compound angle diagonal member define an upper included angle and the compound angle diagonal member and the lower member define a lower included angle, with the upper included angle and the lower included angle preferably being substantially equal. The upper included angle and the lower included angle are preferably between approximately eighty degrees and approximately one hundred ten degrees, and most preferably the upper included angle and the lower included angle are approximately ninety degrees.